Product Overview
Methyl Ethyl Ketone (MEK) ACS Grade — CAS 78-93-3, also sold as butanone — is a fast-evaporating ketone solvent supplied to ACS reagent specifications. It is a colorless, fairly volatile liquid with an acetone-like odor, and it dissolves resins, adhesives, and coating binders that slower solvents leave behind. We stock it in our Taylor, TX warehouse and ship it daily as a fully regulated Class 3 flammable liquid.
This grade is bought by analytical labs running it as an HPLC mobile phase component, by coatings formulators who need a clean, consistent solvent, by manufacturers thinning adhesives and sealants, and by maintenance teams degreasing metal parts where residue matters. If your process is sensitive to trace contamination, this is the MEK to specify.
Why This Concentration
ACS Grade means the material is supplied against the reagent specifications of the American Chemical Society — the benchmark labs specify when a solvent has to behave the same way in every run. For analytical work, extraction steps, and critical formulation, that consistency is the whole point: an off-spec solvent shows up as baseline noise in chromatography or as haze and adhesion problems in a coating.
Pick ACS Grade when purity is a process requirement, not a preference. For routine parts cleaning or rough thinning work where reagent purity adds cost without adding value, a technical-grade solvent is usually the economical call — but for lab benches, QC departments, and formulations you have to defend to a customer, buy the grade that comes with a certificate.
Chemical Profile
MEK is a colorless liquid with a pleasant, pungent, acetone-like odor you will recognize the moment a container is opened. Its formula is C4H8O with a molecular weight of 72.11. It is less dense than water — 0.806 at 68 °F, about 6.7 lb per gallon — and will float rather than sink. It is highly water-soluble, at 100 mg/mL or greater at 66 °F, which distinguishes it from many hydrocarbon solvents. Vapor pressure is significant: 77.5 mmHg at 68 °F rising to 100 mmHg at 77 °F, which is why open containers lose product fast and why vapor control matters in the workspace. Those vapors are heavier than air and can travel along floors toward ignition sources; the flash point is 20 °F, well below any working environment you will operate in. The liquid is stable in normal transportation and does not react with water or most common materials of construction.
Industrial Applications
MEK earns its place in a plant because it dissolves aggressively and flashes off quickly. The main places our customers put it to work:
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HPLC mobile phase: used as a mobile-phase component in reversed-phase liquid chromatography, where reagent-grade consistency keeps baselines flat and retention times repeatable.
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Coatings solvent: carries resins in paints, varnishes, and industrial coatings, then evaporates cleanly so films level and cure without trapped solvent.
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Adhesive thinner: cuts the viscosity of adhesives and sealants for spray or roller application, and cleans uncured adhesive from equipment before it sets.
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Extraction solvent: used in pharmaceutical and process extraction steps where a water-miscible ketone with a low boiling character simplifies recovery.
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Cleaning and degreasing: strips oils, inks, and resin residue from metal parts and machinery ahead of coating or assembly.
Handling & Storage
Treat MEK as what it is: a highly flammable solvent. The signal word is Danger, and the product carries H225 (highly flammable liquid and vapor), H319 (causes serious eye irritation), H336 (may cause drowsiness or dizziness), and EUH066 (repeated exposure may cause skin dryness or cracking) (per the product's GHS classification). The vapor irritates the nose, eyes, and throat, and combustion can produce toxic materials — ventilate before you pour.
Store it cool and well-ventilated, away from heat sources, sparks, and open flame, and keep containers tightly closed to limit evaporation losses. Keep it away from strong oxidizing agents and acids. HDPE and glass containers are appropriate. At the bench, wear solvent-resistant gloves and goggles; the EUH066 statement is a practical warning — bare-hand contact dries and cracks skin with repeated exposure. Ground and bond containers when transferring; with a 20 °F flash point and heavier-than-air vapors, static discharge during a drum transfer is a real ignition scenario, not a theoretical one.
Hazmat & Shipping
This product ships as a fully regulated hazardous material. It moves under UN1193 (per 49 CFR 172.101), proper shipping name Ethyl methyl ketone (per 49 CFR 172.101), Hazard Class 3 flammable liquid (per 49 CFR 172.101), Packing Group II (per 49 CFR 172.101). Every order leaves our dock in UN-spec packaging with correct marks, labels, and shipping papers. We pack and ship Class 3 PG II freight every working day — this is routine for us, and your receiving dock gets a shipment that clears carrier inspection without questions.
Documentation
A Safety Data Sheet ships with every order, available in English, Spanish, French, and Japanese. A lot-specific Certificate of Analysis is available for the material you receive — the COA that matches the lot number on your container, not a generic template. A Technical Data Sheet is also available. If your safety, purchasing, or QC department needs documents before the order ships, ask and we will send them ahead.
Why Buy from Alliance Chemical
We are a stocking distributor, and hazmat is our daily work. MEK ACS Grade ships from our Taylor, TX warehouse in DOT-compliant packaging — quarts and gallons for bench and small-batch work, 5-gallon pails for production, 55-gallon drums for bulk consumption. Our shipping and handling guidance is reviewed by Andre Taki, DOT Hazmat Specialist, and the crew that packs your order handles Class 3 flammables every day. You get the right packaging, the right paperwork, and a straight answer when you call about lead times or documentation.
